Pump system

ABSTRACT

A method can include operating a pump system; determining a condition associated with the pump system; and controlling the pump system based at least in part on the condition.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/715,898, filed Dec. 16, 2019, which claims the benefit of andpriority to U.S. Provisional Patent Application No. 62/780,282, filedDec. 16, 2018, both of which are incorporated herein by reference in itsentirety.

BACKGROUND

Various types of equipment can be utilized in a subterraneanenvironment. As an example, a pump system can be utilized to move fluidin a well in a subterranean environment.

SUMMARY

A method can include operating a pump system; determining a conditionassociated with the pump system; and controlling the pump system basedat least in part on the condition. Various other apparatuses, systems,methods, etc., are also disclosed.

This summary is provided to introduce a selection of concepts that arefurther described below in the detailed description. This summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the described implementations can be morereadily understood by reference to the following description taken inconjunction with the accompanying drawings.

FIG. 1 illustrates an example of a system that includes a pump disposedin a subterranean environment;

FIG. 2 illustrates an example of a method;

FIG. 3 illustrates an example of an instrumented pump system andexamples of plots pertaining to operation of the pump system;

FIG. 4 illustrates examples of plots pertaining to operation of a pumpsystem;

FIG. 5 illustrates examples of plots pertaining to operation of a pumpsystem;

FIG. 6 illustrates an example of a system;

FIG. 7 illustrates an example of a machine model;

FIG. 8 illustrates an example of a method;

FIG. 9 illustrates an example plot of some factors associated withstress corrosion cracking (SCC);

FIG. 10 illustrates an example of a method;

FIG. 11 illustrates an example of a pumping unit; and

FIG. 12 illustrates an example of computing system and a networkedcomputing system.

DETAILED DESCRIPTION

The following description includes the best mode presently contemplatedfor practicing the described implementations. This description is not tobe taken in a limiting sense, but rather is made merely for the purposeof describing the general principles of the implementations. The scopeof the described implementations should be ascertained with reference tothe issued claims.

As an example, a system may be a pump system that includes one or moremechanisms to reciprocate a rod string where the rod string can includerods that are joined via couplings. For example, a rod can includeopposing threaded ends, which may be referred to as pins, where each ofthe ends can be threaded into mating threads of a coupling. In such anexample, a long rod string can be assembled that is made up of a seriesof rods where the rods are joined by couplings. Such a rod string may bemeters in length.

As an example, a rod may be a sucker rod. A sucker rod can be a steelrod that is used to make up a mechanical assembly between the surfaceand downhole components of a rod pumping system. As an example, a suckerrod may be a non-standardized length or a standardized length. As anexample, a standardized length of a sucker rod may be in a range fromabout 25 ft to about 30 ft (e.g., about 7 m to about 9 m).

As an example, a pumping system can be an artificial-lift pumping systemthat can be powered using a surface power source to drive a downholepump assembly. As an example, a pumping system can include a beam andcrank assembly that creates reciprocating motion in a rod string thatconnects to the downhole pump assembly. In such an example, the downholepump assembly can include a plunger and valve sub-assembly that canconvert reciprocating motion to vertical fluid movement.

As an example, an electric motor may be utilized to reciprocate a rodstring, optionally via one or more belt or chain drives. For example, abelt driven pumping unit can include a belt that is coupled to a rodstring for reciprocating the rod string vertically within a well as thebelt is driven by an electric motor. As an example, a pump may be asucker rod pump that includes a sucker rod string.

FIG. 1 shows an example of a system 100 that includes a pump assembly101 as driven by a pump drive system 104 that is operatively coupled toa controller 122. In the example of FIG. 1 , the pump assembly 101 anddrive system 104 are arranged as a beam pump. As shown in FIG. 1 , awalking beam 138 reciprocates a rod string 144 that includes a polishedrod portion 146 that can move in a bore of a stuffing box 150 of a wellhead assembly that includes a discharge port in fluid communication witha flowline 152. The rod string 144 can be suspended from the walkingbeam 138 via one or more cables 142 hung from a horse head 140 foractuating a downhole pump 110 of the pump assembly 101 where thedownhole pump 110 is positioned in a well 102, for example, near abottom 112 of the well 102.

A well in a subterranean environment may be a cased well or an open wellor, for example, a partially cased well that can include an open wellportion or portions. In the example of FIG. 1 , the well 102 includescasing 106 that defines a cased bore where tubing 108 is disposed in thecased bore. As shown, an annular space can exist between an outersurface of the tubing 108 and an inner surface of the casing 106.

In the example of FIG. 1 , the walking beam 138 is actuated by a pitmanarm (or pitman arms), which is reciprocated by a crank arm (or crankarms) 134 driven by a prime mover 130 (e.g., electric motor, etc.). Asshown, the prime mover 130 can be coupled to the crank arm 134 through agear reduction mechanism, such as gears of a gearbox 132. As an example,the prime mover 130 can be a three-phase AC induction motor that can becontrolled via circuitry of the controller 122, which may be connectedto a power supply. The gearbox 132 of the pump drive system 104 canconvert electric motor torque to a low speed, high torque output fordriving the crank arm 134. The crank arm 134 can be operatively coupledto one or more counterweights 142 that serve to balance the rod string144 and other equipment as suspended from the horse head 140 of thewalking beam 138. A counterbalance may be provided by an air cylindersuch as those found on air-balanced units.

The downhole pump 110 can be a reciprocating type pump that includes aplunger 116 attached to an end of the rod string 144 and a pump barrel114, which may be attached to an end of the tubing 108 in the well 102.The plunger 116 can include a traveling valve 118 and a standing valve120 positioned at or near a bottom of the pump barrel 114. Duringoperation, for an up stroke where the rod string 144 translatesupwardly, the traveling valve 118 can close and lift fluid (e.g., oil,water, etc.) above the plunger 116 to a top of the well 102 and thestanding valve 120 can open to allow additional fluid from a reservoirto flow into the pump barrel 114. As to a down stroke where the rodstring 144 translates downwardly, the traveling valve 118 can open andthe standing valve 120 can close to prepare for a subsequent cycle.Operation of the downhole pump 110 may be controlled such that a fluidlevel is maintained in the pump barrel 114 where the fluid level can besufficient to maintain the lower end of the rod string 144 in the fluidover its entire stroke.

As an example, the system 100 can include a beam pump system. Asexplained, a prime mover can rotate a crank arm, whose movement isconverted to reciprocal movement through a beam. The beam can includecounterweights or a compressed air cylinder to help reduce load on thebeam pump system during the upstroke. The beam can be attached to apolished rod by cables hung from a horsehead at the end of the beam. Thepolished rod can pass through a stuffing box and be operatively coupledto the rod string. As explained, the rod string can be lifted andlowered within the production tubing of a cased well by the reciprocalmovement of the beam, enabling the downhole pump to capture and liftformation fluid(s) in a direction toward surface (e.g., with a flowvector component against gravity) in the tubing and through a pumpingtee that directs the fluid into a flowline.

As an example, the prime mover may be an internal combustion engine oran electric motor that provides power to the pumping unit. As anexample, a prime mover can deliver highspeed, low-torque power to a gearreducer, which converts that energy into the low-speed, high-torqueenergy utilized by the surface pump. As shown in FIG. 1 , a beam pumpingunit, beam pump system or merely beam pump, converts the rotationalmotion of the prime mover into a reciprocating vertical motion thatlifts and lowers a rod string connected to a subsurface pump.

Some aspects of a system can include prime mover type; pumping unitsize, stroke length and speed setting; rod and tubing diameter; anddownhole pump diameter, for example, based at least in part on reservoirfluid composition, wellbore fluid depth and reservoir productivity.

As an example, a design framework may facilitate some decisions as todesign, for example, to arrive at a desired pump speed to attainproduction targets without overloading the system or overwhelming theformation's ability to deliver fluids to a wellbore.

Beam pumps may be constructed in a variety of sizes and configurations.Some systems include design aspects that can aim to better managetorque, rod wear and/or footprint. For example, as to some designaspects, consider locating counterweights on the crank arm or on thebeam and use of compressed air rather than weight to assist in loadbalancing. Further examples can involve changes to crank, gear reducerand motor position relative to the beam, as well as alternative beamdesigns, where such factors may change system loading.

As an example, a system may place heavier rods, or sinker bars, in thelower section of the rod string to keep the rod string in tension, whichreduces buckling and may help prevent contact with the tubing wall. Rodstrings may also include stabilizer bars between sinker bars tocentralize the rods, further reducing tubing wear.

Rod guides, which may be made of reinforced plastics, may be molded ontosteel rods at depths where engineers may predict the rods willexperience side loading due to a deviated wellbore path. The guides canact like bearings between the tubing wall and the rod to prevent rod andtubing wear. Sliding guides may be able to move between molded guidesduring the pump cycle, aiding production by scraping paraffin from thetubing wall, which helps prevent well plugging. A rod rotator or tubingrotator may be used to rotate the rod a small fraction of a revolutionon each stroke of the pumping unit to further extend rod string life. Asan example, slow rotation of rod guides may help scrape paraffin fromthe tubing wall.

Sucker rods may be connected to the surface pumping unit by a polishedrod. A polished rod, for example, made of standard alloy steel andhard-surface spray metal coating, can support loads created during apump cycle and help to ensure a seal through a stuffing box at a top ofa well. The stuffing box can be attached to a wellhead or pumping teeand can form a low-pressure tight seal against a polished rod. The sealcan form a barrier between a well and atmosphere and may allow flow tobe diverted into a flowline, for example, via a pumping tee.

FIG. 2 shows cut-away view of the downhole pump 110, which shows aportion of a rod 144, the pump barrel 114, the plunger 116, thetraveling valve 118, and the standing valve 120 positioned at or nearthe bottom of the pump barrel 114. Further shown in FIG. 2 are anopening 117 for inflow of fluid(s) and a chamber 119, which is shown tobe in a space disposed at least in part between the traveling valve 118and the standing valve 120. The downhole pump 110 is an example of apump mechanism that can move fluid, where such fluid can differ withrespect to time. As an example, fluid can be liquid and/or gas. As anexample, fluid can include entrained solids, semi-solids, etc.

FIG. 2 shows an example of a method 200 with actions or states 210, 220,230 and 240, which can be portions of a cycle (e.g., cycle actions,cycle states, etc.). As to the action 210, the pump 110 has achieved amaximum downward reach of a cycle. In the action 220, a beam can beginits upward movement such that the rod 144 and plunger 116 are pulledupwardly, forcing the ball of the traveling valve 118 to be on to itsseat. This upward movement reduces the pressure in the pump chamber 119until it is less than the pressure at the pump intake 117. The ball inthe standing valve 120 can then come off its seat, allowing formationfluid to enter via the intake 117 and flow to the pump chamber 119. Asto the action 230, the standing valve 120 is closed as the plunger 116is at the end of the upward stroke. As to the action 240, as the plungertravels down, the pump chamber 119 experiences a pressure increase,pushing the ball in the traveling valve 118 off its seat. The action 240allows the formation fluid to flow from the pump chamber 119 into thetubing via the plunger 116 as the plunger 116 continues to movedownwardly in the pump 110. A cycle can include the actions 210, 220,230 and 240. Such a cycle can be repeated thousands of times per day.The fluid displaced into the tubing may be carried toward surface onsubsequent upward strokes of the plunger 116.

FIG. 3 shows an example of a system 300 with a controller 322 andvarious sensors that include position sensors and load sensors. Forexample, as to position sensors consider an inclinometer 332 andproximity switches 333 (e.g., Hall Effect sensors); and, for example, asto load sensors, consider a load cell 334, current sensors 335 and abeam transducer 336. Such sensors can be operatively coupled to thecontroller 322 (e.g., via wire and/or wirelessly through wirelesscircuitry). As an example, the load cell 334 can be a load-capabledynamometer attached to the polished rod for acquiring dynamic data,which may be transmitted and/or otherwise accessed by one or more piecesof equipment.

A controller can utilize sensor data to calculate rod loading (e.g., asurface condition) and, coupled with various models (e.g., algorithms),to estimate downhole pump fill (e.g., a downhole condition).

A frequent challenge to downhole pump operation is the entry of gas intothe pump, leading to fluid pound or gas interference. Fluid pound occurswhen the plunger travels down quickly through low-pressure gas and thensuddenly hits liquid fluid; the resulting compressive shock can damagerod strings and the prime mover gearbox. Gas interference is lessdamaging and occurs when the plunger travels down through high-pressuregas. Both conditions can reduce system efficiency.

To combat gas interference, gas separators may be placed below the pumpto redirect the gas into the wellbore annulus around the pump. Othermodifications may be made to a completion to counter or reduce theeffects of heavy oil and sand or other produced solids.

Operators can diagnose gas interference, liquid fluid pound severity andvarious other operating conditions using a dynamometer, which plots rodtension versus displacement measurements at the surface and downhole atthe pump. The shape of an ideal downhole graph, called a dynamometercard, is rectangular and indicative of a full pump. Deviations from theideal shape can indicate performance issues, such as gas interference,system leaks, stuck pumps, parted rods and various other anomalies thatmay be identified and accounted for automatically or through manualintervention.

Systems available for improving pump efficiency and protecting thepumping system include pumpoff controllers and variable speed drives(VSDs). When dynamometer values indicate gas interference, pumpoffcontrollers can be programmed to turn off the surface unit for a setperiod, calculated to allow enough time for fluid to migrate through thereservoir and into the wellbore. Such an approach tends to be lesscomplex and less costly than using VSDs but tends to be limited as toeffectiveness to areas where operators have sufficient productionhistory to obtain accurate estimates of how long to shut down the unit.As an example, based on dynamometer measurements, a VSD may act toreduce the pump speed instead of turning the pump off. Such an approachallows time for the pump to become clear of gas or for liquid levels inthe wellbore to rise without having to shut down. Use of VSDs may beparticularly effective in very-low-permeability formations and shales,where the time required for oil to migrate into the induced fracturesand into the wellbore can be difficult to predict even across a singlefield.

As rod pumping systems are relatively inexpensive to install and operateand have a relatively long life, rod pumping systems tend to be a quitecommon form of artificial lift. They tend to be “simple” machines thathave a long and well-documented history in the industry and they tend tobe adjustable to meet changing well or field conditions.

The use of rod pumps is likely to increase as the industry continues toexpand its involvement in shale formations and other unconventionalplays, which require operators to use high numbers of relativelylow-flow-rate wells to exploit each field. Initial high pressures andhigh production volumes from these hydraulically fractured horizontalwells are quickly followed by low bottomhole pressures and steepproduction decline rates; production is possible through the use ofartificial lift systems, of which rod pumps tend to be efficient atthese low rates.

Even if not the initial artificial lift system of choice, rod pumpingsystems tend to be installed on many types of wells as production ratesdecline and the economics of initial systems are undone by higheroperating costs. As a consequence, rod pumping systems are likely tomaintain their position as a frequently deployed artificial lifttechnique.

A dynamometer is an instrument used in sucker-rod pumping to record thevariation between the polished rod load and the polished roddisplacement.

A dynamometer card is a record made by a dynamometer. An analysis ofdynamometer measurements may reveal a defective pump, leaky tubing,inadequate balance of the pumping unit, a partially plugged mud anchor,gas locking of the pump or an undersized pumping unit. A dynamometercard may be in the form of a graph, such as a dynagraph.

FIG. 3 also shows a surface condition plot 370 and a downhole conditionplot 390, which are plots of load versus distance with respect to time,for example, with respect to one or more cycles that include the actions210, 220, 230 and 240 of FIG. 2 .

As to the downhole condition plot 390, as mentioned, it can be based ona model. Such a model may include various types of factors such as, forexample, velocity of sound in a rod, modulus of elasticity of thematerial of rods, length of a rod string, number of increments inposition, number of discretization in time, pump velocity (e.g., cyclesper minute, stroke per minute, etc.), rod stroke length, rod diameter,specific weight of rod material, a factor of dimensionless damping,specific gravity of fluid, diameter of tubing, etc.

As an example, the following equation may be utilized to model wavepropagation:

$\frac{\partial^{2}{u( {s,t} )}}{\partial t^{2}} = {{v^{2}\frac{\partial^{2}{u( {s,t} )}}{\partial s^{2}}} - {c\frac{\partial{u( {s,t} )}}{\partial t}}}$

The foregoing equation is a one-dimensional transient partialdifferential equation of a second order known as the one-dimensionalwave equation with viscous friction. The solution returns thedisplacement of a point of a rod and time. The foregoing equation,without gravitational effects, is the so-called Gibbs equation. Thefirst term in the above equation accounts for the newton accelerationforce while the second term accounts for the spring force; noting thatv² accounts for the propagation velocity as a function of Young'smodulus and density

$( ( \frac{E}{\rho} )^{0.5} ),$

and c is a damping term.

Friction and gravity terms may be added to the foregoing equation, forexample, as follows:

−C(s) + g(s)${C(s)} = {\delta{{\mu(s)}\lbrack {{Q(s)} + {{T(s)}\frac{\partial{u( {s,t} )}}{\partial s}}} \rbrack}}$

As an example, another approach can be utilized, which can include thefollowing equations:

vx(xi,t)=vx(xi,ti−1)+(dt/dm)*Ftot_x(xi,t−1)/fc;

vz(xi,t)=vz(xi,t−1)+(dt/dm)*Ftot_z(xi,t−1)/fc

omega(xi,t)=omega(xi,t−1)+(dt/dI)*Mtot_y(xi,t−1)

-   -   vx: velocity in horizontal direction in global coordinate system    -   vz: velocity in vertical direction in global coordinate system    -   omega: angle velocity describing the bending in each defined        segment    -   t: discretized time    -   xi: discretized position    -   dt: time increment    -   dm: mass per segment    -   dI: bending moment    -   Ftot_x: sum of internal and external forces in horizontal        direction (spring force, bending    -   force, solid friction)    -   Ftot_z: sum of internal and external forces in horizontal        direction (spring force, bending    -   force, solid friction, gravity)    -   Mtot_y: bending moment

In another embodiment a 3D model is used. Compared to the 2D model the3D model allows to predict and/or observe helical buckling. For example,consider the 2D model being extended by the following terms:

vy(yi,t)=vy(xi,ti−1)+(dt/dm)*Ftot_x(yi,t−1)/fc;

omega_x(yi,t)=omega(yi,t−1)+(dt/dI)*Mtot_x(yi,t−1)

omega_phi(xi,t)=omega_phi(Phi_i,t−1)+(dt/dJ)*Mtorsiona_z(Phi_i,t−1)

Above, a damping adjustment factor (fc) is included, as well as atorsion term (Mtorsiona_z).

The coupled equations can be solved by coordinate transformation from aninertial coordinate system to the orientation of each discretized pointinto axial and normal directions. The partial differential equations arecoupled through orientation vectors, which can be dynamically calculatedfor each position. For example, after coordinate transformation, partialdifferential equations are determined in axial and lateral direction andone that describes the change of bending angle between segments overtime.

As an example, a three-dimensional system can be solved via recursiveintegration for velocity and solving again with integration over time todetermine position in horizontal and vertical directions as well asbending angle.

As an example, friction force can be calculated from the normal force ofeach point and the friction coefficient of each point and points in theaxial direction. The bending spring force is implicitly calculated fromthe change in orientation angle between two neighboring points. Theangle wave velocity is calculated from the ratio of the moment ofinertia of a cylinder segment to the bending stiffness of a cylindricalrod.

As an example, for a system model, the partial differential equationsare solved in each domain in a recursive form by double numericalintegration over time.

As mentioned, dynacard plots may be utilize in a system, a method, acontroller, a model, etc. As an example, dynacards plots can estimatedownhole force versus displacement. As an example, an approach can be torelate that to pump load force, particularly pressure. As an example, ifthe ratio of acceleration to the Earth's gravitational constant fluidacceleration term adds variation to the dynacard, that can increase thedifficulty of dynacard classification and gas content estimation. As anexample, an approach can include subtracting the acceleration force fromthe downhole force estimate such that the downhole dynacard becomessmoother and easier to relate to the pump force.

As an example, a load model may be utilized in a system, a method, acontroller, a model, etc. For example, a load behavior of a pump can befor health pump behavior, which may cover a portion of a pump or a fullpump, including high pressure gas or low pressure gas (e.g., fluidpound).

As an example, consider the following load model that covers these casesas described by isothermal compression.

-   -   Upstroke: vaxial<(downhole speed in upwards direction)    -   Fn_up=ρ g h Ap+F_frictionpump (Fluid weight)    -   Downstroke: vaxial>0(downhole speed in downwards direction)    -   x>x0    -   Fn_dn=Ap (ρ g h (1−(xx−x0)/(xx-x))—F_friction_pump    -   (fluid weight pushing against compressed gas and pump friction)    -   else    -   Fn_dn=−ρ g h Ar —F_friction_pump (buoyancy and pump friction)

As an example, where buckling can be a concern, a model can bemultidimensional, which may be a 3D spatial model that includes one ormore buckling terms. Rod buckling can be due to various causes,including, for example, fluid pound (e.g., pounding fluid). Rod bucklingcan also result from improperly sized and centralized sinker bars (e.g.,above the pump to provide the additional weight). Sucker-rod bucklingcan cause excessive rod- and/or coupling-on-tubing wear above the pump.Buckling at the bottom of a rod string also may cause prematurevalve-rod or pull-tube failures. As mentioned, sinker bars can beutilized, which can help to reduce negative loadings and centralize arodstring and tubing. For example, sinker bars can reduce negativeloadings created by buckling of a rodstring during a pumping cycle whilekeeping the rodstring in tension. Sinker bars can be equipped with astrong pin to keep connections together during tough cyclic loadsdownhole. As an example, stabilizer bars and tubing centralizers canhelp to centralize certain portions of a rodstring and/or tubing andhelp to keep rod couplings off the tubing, thereby reducing tubing wearin susceptible areas.

Various equations may be utilized with various types of pumpingequipment. As an example, consider one or more beam pumping units (e.g.,sizes from API 25 to 1280, etc.). As an example, a pumping unit can beone or more types of pumping units described herein or another type ofpumping unit such as, for example, a beam-balanced pumping unit, aTorqMax enhanced-geometry pumping unit, a FlexLift low-profile pumpingunit, a curved beam pumping unit, a HSU hydraulic stroking unit, aself-contained, portable, trailer-mounted pumping unit, etc.

As an example, a multi-dimensional spatial model can help to improvemodeling of buckling, detection of buckling, control as to reduce riskof buckling and/or consequences of buckling, etc. As an example, amulti-dimensional model can include terms that provide for adjustment toacceleration, which can result in a more precise pump load model, whichcan allow for improved gas estimates and stroke length.

As an example, a system may include a 3D model, a pressure model and aload model. As an example, a system can provide for generation,recognition of and/or control of dynacard data. As an example, a systemcan include generating a specialized dynacard, for example, consider adynacard with Newton inertial force estimates subtracted. As an example,a model can be composed of multiple models. For example, a model can becomposed of a multi-dimensional model, a pressure model and a loadmodel. As an example, a model can include one or more other models,which may be referred to as, for example, sub-models.

One or more of the foregoing equations may be implemented as a system ofequations, for example, in a system that utilizes a combination ofclassification and system identification where the system of equationscan represent a deviated well model with an advanced solid frictionmodel. As an example, the system of equations may be referred to as asystem model or a reference model.

As mentioned, downhole condition can be better understood through use ofa model. Where downhole condition is understood to at least some extent,control may be more effective, which may aim to reduce wear, increaseefficiency, etc.

As an example, a method can use a wave propagation solution to provide astarting point for a load model for a simulation. For example, considera set of initial conditions given by output of a computational solverfor a wave propagation model for solving a load model via acomputational solver. As to some differences, a wave propagation modelcan include inputs of surface force and position and output as a pumpmodel; whereas, a system model can include inputs of surface force andpump model and outputs of position and force at various locations; orinputs of position and pump model and outputs of position and force atvarious locations.

In one embodiment the system model can be based on a 2D model, where anequivalent horizontal curvature is projected in one axis. In such anexample, the bending forces may be accounted for, although this cancontribute to a small gravity error. As mentioned, system dynamics canbe described by three coupled partial differential equations that can besolved by double numeric integration in a discrete domain. In such anexample, coupling can be related to the normal and lateral forces thatare derived from the dynamic well orientation in each defined segment.

FIG. 4 shows a plot of surface condition 470 and downhole condition 490with control, where, in comparison to the plot of FIG. 3 , is shown toreduce load extrema of the surface. FIG. 4 also shows a plot 495 thatincludes pump direction, crank velocity, rod velocity and downholevelocity as distance with respect to time (velocity) versus degree from0 degrees to 360 degrees, which represents a single cycle.

FIG. 5 shows some examples 500 of dynamometer card shape variations,which may facilitate control. The shapes correspond to dynamicconditions such as a perfect trace, rod stretch, partial pump fill,acceleration and harmonics, low filage, tapping down, tapping up, wornbarrel, delayed tv sensing, bad tv, bad sv, pounding hard, gas lock orbad sv, deep rod part, excessive harmonics, high fluid level, excessivefriction, excessive rod stretch, stuck pump, bad position signal, badload signal or galded pump, etc.

FIG. 6 shows an example of a system 600 that includes a rod 605, a pumpmodel block 610 (e.g., actual physics), a tuning block 630 and a systemmodel block 650. In the example of FIG. 6 , a measurement such as aforce measurement represents force applied to the rod 605, which is aninput to the pump model block 610 and to the system model block 650. Asshown, the blocks 610 and 650 can provide outputs such as positionand/or pressure. Where those outputs differ between the blocks 610 and650, a prediction error can be determined, which can be input to thetuning block 630 that can interact with the system model block 650 fortuning of the system model. Such tuning aims to improve the ability ofthe system model block 650 to model the actual physical system.

As shown, the pump model block 610 can include various sub-blocks suchas a full pump template 611, a high pressure gas template 612, a lowpressure gas template 613, a valve leak template 614 and one or moreother templates 615, etc.

The system 600 allows for rod pump monitoring and system identificationthrough the system model of the system model block 650. The system modelcan be or include, for example, the aforementioned three coupled partialdifferential equations.

While sucker rod pumps are mentioned, one or more types of artificiallift technologies (e.g., KUDU hydraulic pumps, etc.) may be modeled in asystem such as the system 600. As to sucker rod pumps, such pumps caninclude a series of rods that form a unified rod that has a length of atleast approximately 30 feet (e.g., approximately 10 meters).

As an example, a pump may be implemented in the water industry, thewaste industry, a general processing/manufacturing plant, etc. Thesystem 600 can provide for condition monitoring of pump equipment.

The system 600 can implement an approach involving parameter estimation,observers and system identification to monitor the operation of a rodpump. The information of interest relates to pump efficiency, pumpspeed, gas content, integrity of pump, integrity of the rods, rodguides, tubing and casing.

As mentioned, pump technology can utilize surface measurements of forceand position. These measurements can be used to calculate via a wavepropagation model an estimate for downhole force and position over time.The results can then be used to plot the force versus position of thedownhole plunger position (see, e.g., plots of FIGS. 3, 4 and 5 ). Aso-called downhole dynacard (e.g., dynamometer card) can be taken as abasis to assess a pump system and pump performance. As mentioned, asimplistic approach uses knowledge of the geometry and materialproperties, but makes no assumption about the physics of the pumpoperation.

The system 600 can utilize parameter and observer techniques fromcontrol theory. For example, a system can include an input thatstimulates the system and an output that can be measured. Parallel tothe running physical system (see, e.g., the pump model block 610), areference model with an equivalent mathematical structure (see, e.g.,the system model block 650) can be running that receives the samestimulus as the physical system.

In the example system 600 of FIG. 6 , the system model can be based oncorresponding physics that describe dynamic dependencies between inputand output. For a physical installation, the mathematical structure canbe parametrized, while allowing for some variation for at least some ofthe parameters and states with higher uncertainty. The result ofreference model is a prediction of the measurement output (e.g.,position, pressure, etc.). In the example system 600, a goal of thereference model can be to find system states and fine tune systemparameters, such that the measurement prediction and the realmeasurement become consistent (e.g., prediction error converges tozero). Provided that the dependency between parameters and predictionerror is unique, the best parameter and system estimate may be reachedwhen the prediction error reaches a minimum deviation.

As explained, a basic rod pump installation includes a downholedisplacement pump that includes two valves, a traveling valve in theplunger and a standing valve on the bottom. It is coupled through a rodassembly from downhole to surface to an actuator that provides themoving force. In hydraulic pumps, this actuator is implementedhydraulically, in sucker rod pumps it is driven through a mechanicalassembly from a motor.

On the upward motion the standing valve at the bottom is open and fluidis sucked in to the bottom side of the below the piston. While the fluidon top of the piston is lifted up. On the downstroke the traveling valveopens and the standing valve is closed, which allows the barrel on topof the piston to refill with fluid.

As an example, the system 600 can be utilized for rod pump automationand diagnostics software, possibly implemented in SCB2020, an RTU or onthe cloud. As mentioned, the system 600 may be utilized for instrumentedsucker rod pumps and/or hydraulic pumps.

The system 600 may be integrated into one or more well site automationproducts in the field, integrated cloud products (for instance reservoirmonitoring, modeling, validation, planning, optimization, etc.), alsostatistical data analytics for process and design improvements.

FIG. 7 shows an example of the pump model block 610, the system modelblock 650 and a machine model 750, which may be utilized in combinationwith the blocks 610 and 650 and their input(s) and/or output(s), forexample, for purposes of classification, prediction, etc. For example,the machine model 750 can include one or more inputs and one or moreoutputs where nodes can be “hidden” as in a neural network model. Themachine model 750 can be trained using training data, which can adjustweights, etc., as may be associated with the nodes. A trained machinemodel can be utilized for purposes of classification. For example, givena particular input to the machine model 750, as a trained machine model,it may classify a pump system as being in a particular state. As toexamples of states (e.g., dynamic cyclical states), consider one or moreof the examples 500 of FIG. 5 .

As an example, training data may be generated using a physics-basedmodel of a pump system. For example, the aforementioned coupled systemof partial differential equations may be utilized to simulate operationof a pump system and optionally associated well parameters, fluidparameters, etc. Such data may include inputs and outputs that can beutilized to train a machine model such as a neural network model. As anexample, one or more features of the TENSOR FLOW framework may beutilized for purposes of machine modeling (Google, Mountain View,California). As an example, training may be in real-time, parallel tosimulation. In such an example, as training data are generated, machinelearning can proceed. As an example, training data may be generated inadvance of machine learning. For example, consider generating a databaseof states from a physics-based model where various states can beselected for use as training states for training a machine model togenerated a trained machine model for a particular type of pump, type ofwell, type of fluid, etc.

As an example, output of a machine model (e.g., a trained machine model)can be utilized to adjust a physics-based model or a pump system. Forexample, consider identification of a state via classification where thestate is characterized by one or more physical parameter values that canbe utilized to adjust the physics-based model.

As an example, the machine model 750 may be utilized to determine one ormore aspects of a well. For example, for a deviated well, the machinemodel 750 may output a state that is a well state that physicallydescribes deviation of a well. As an example, the machine model 750 caninclude classifying one or more types of fluids, optionally with respectto one or more well parameters (e.g., well depth, etc.).

As an example, a system can use a machine leaning approach based onregression with a predetermined mathematical structure based on physics(see, e.g., coupled partial differential equations). In artificialintelligence (AI) terminology, an approach can be or include a truemodel-based approach, rather than merely a crude data driven modelapproach. As an example, a combination of classification with finetuning of a wave propagation model through system identification can beimplemented for one or more purposes.

As an example, one or more kernel techniques may be utilized forpurposes of learning. In machine learning, kernel methods are a class ofalgorithms for pattern analysis, which include the support vectormachine (SVM). A general task of pattern analysis is to find and studygeneral types of relations (e.g., clusters, rankings, principalcomponents, correlations, classifications) in datasets, which can bedatasets such as in FIG. 5 . As an example, in various machine learningapproaches, data can be transformed into feature vector representationsvia a feature map. In kernel approaches, a specified kernel may beutilized (e.g., a similarity function over pairs of data points in rawrepresentation).

A kernel technique can utilize one or more kernel functions, whichenable them to operate in a high-dimensional, implicit feature spacewithout computing coordinates of data in that space; rather, involvingcomputing the inner products between the “images” of pairs of data inthe feature space. Such an operation can be often computationally moreefficient than the explicit computation of the coordinates. As anexample, a kernel functions can be for one or more of sequence data,graphs, text, images, vectors, etc.

As an example, a system can include one or more features for patternrecognition and/or pattern analysis. As an example, a control system mayaim to generate a particular type of pattern (e.g., a dynacard pattern,etc.). As an example, a control system can include a desired targetpattern (e.g., with appropriate characteristics) and can issue controlinstructions (e.g., commands, etc.) to a pump system that aims toachieve the desired target pattern. In such an approach, one or moretypes of errors may be determined via a comparison of one or morepatterns. For example, an actual pattern may be compared to a pluralityof pre-determined patterns (e.g., optionally specialized for aparticular installation, etc.) to identify operational conditions thatcan be amenable to control to achieve a desired, target pattern (e.g.,or to more closely approach the desired, target pattern). As mentioned,a system can include one or more models, which can be trained machinemodels or other models. Such a system may receive data during a pumpingoperation and utilize such one or more models to determine anappropriate control action or actions and then issue one or moreinstructions to a pump system to control the pumping operation. Asmentioned, such a system may operate in part via a physics-based model,which may be utilized, for example, for generating patterns that may, inturn, be utilized for purposes of model training to generate a trainedmodel that can be implemented for control, optionally alone or incombination with one or more physics-based models. As an example, one ormore plots may be pixelated to be turned into images (e.g., 2D pixelimages, etc.) for purposes of training, pattern recognition, errordeterminations, control, etc.

The approach of FIG. 7 can improve accuracy of a wave propagation model,particularly in one or more deviated wells. Such an approach can improveaccuracy of predicted rod lifetime, accuracy of stroke length, etc.

As mentioned, the system 600 can use mathematical structures based onphysics of pumping and a comprehensive system model for systemidentification and monitoring.

Referring again to the system 600, it can operate as a dynacardestimator. As an example, the system model can be based at least in parton the classical structure of the Gibbs equation in discrete form withan additional term for solid friction. While Gibbs mentions one form ofa friction model, one or more Coulomb friction models may beimplemented.

In a classical approach, position and force measurement at surface aretreated as an input. In contrast, in the system 600, force can beutilized as an input and position can be an output. The physical systemincluding rod, tubing, rod guides, well deviation and pump can be partof a dynamic system that is stimulated with a force at surface and thatresponds with a change in position at surface. Downhole force andposition and downhole pump operation can be calculated implicitly as abyproduct of the system model.

To get the best estimate of the system, tuning can be implemented forone or more system parameters and state variables of the reference modelof the system, for example, to minimize prediction error betweenmeasured and predicted position at surface.

As an example, a system model can be complemented with one or more othermeasurements as may be available, such as surface pressure in the tubingand casing. By monitoring the system state over time, degradingperformance can be detected. In response, one or more control signalsmay be issued to control one or more parameters of a physical pumpsystem.

A comprehensive system model can have a valuable effect on simulation.Simulation results for surface and downhole state can be used togenerate a large variety of different configuration examples that can beused, for example, for machine learning. A physics-based model can givea good reference of truly expected downhole and surface dynacards thatcan be used as a reference for the true observations at the well.

Standard dynacard shapes (e.g., patterns) as may be shown in FIG. 5 maybe, to some extent, considered idealized as real acquired dynacards canvary substantially. Noise reduction through low pass filtering or areduced number of the Fourier decomposition in the Gibbs method have alow pass filter effect that reduces the sharpness of edges and corners.If the wave propagation is calculated with higher dynamics, that canresult in dynacards that have a lot more high spatial frequencycontents. Part of them may be attributed to noise, some of the ripple offorce versus range can be attributed to a true system variation that isimpacted by the reflective waves along the pump.

As an example, signal content in these higher spatial frequencies can beused as an additional independent measurement output, since its contentsaffect the dynamic component of solid friction in deviated wells.

As an example, a method can provide for better design validation duringcommissioning. As an example, a method can provide for betterdiagnostics of rod, rod guide and tubing wear. As an example, a methodcan provide for lifetime prediction. As an example, a method can providefor failure and wear detection.

As an example, a method can get a better estimate of a system, such asestimates as to one or more of damping, friction, pump fill factor, pumpfailure type, rod/rod guide wear, etc. Such estimates may be utilizedfor purposes of control.

As an example, a method can help to reduce noise impact. As an example,a method can create an extensive and comprehensive database forreference examples for machine learning. As an example, a method caninclude training one or more machine models to generate one or moretrained machine models. Such trained machine models may be utilized forone or more purposes, which can include classification (e.g., stateidentification). As an example, a controller may operate onclassification as output by a trained machine model.

As to various aspects of an environment, as mentioned, a well may bedeviated. For example, a well can include a portion that is deviatedfrom vertical. In such an example, gravity, friction, fluid flow, etc.,can differ from that of a vertical well. As to fluid or fluids (e.g.,and/or pressure, temperature, etc.), consider chemical environments thatcan be detrimental to pump system equipment and/or operation.

FIG. 8 shows an example of a method 800 that includes an operation block810 for operating a pump, an acquisition block 820 for acquiring datavia one or more sensors during operation of the pump, a determinationblock 830 for determining forces associated with operation of the pump,a determination block 840 for making one or more determinations as tooperation of the pump, a pull block 850 for pulling equipment based onone or more of the determinations prior to failure and a control block860 for controlling operation of the pump to extend time (e.g.,lifetime) and/or to meet one or more performance indicators (e.g., PIs).As shown, the method 800 can be a control loop, for example, where theblock 860 can continue to the block 810. Such a control loop may proceeduntil a decision is made to enter the pull block 850 to pull equipment.

As shown in the example of FIG. 8 , the block 840 includes adetermination block 842 for determining a rod failure time for one ormore rods of a sucker-rod pump, a determination block 844 fordetermining a rod guide failure time for one or more rod guides, adetermination block 846 for determining a tubing wear condition where aguide may become worn such that a rod or other component is causingtubing wear, and a determination block 848 for making one or more otherdeterminations.

As mentioned, a method can include determining one or more normalforces, which can be normal to a longitudinal axis of a component of apump such as a rod of a pump. As an example, a control system caninclude circuitry that can determine one or more normal forces, whichcan be normal to a longitudinal axis of a component of a pump such as arod of a pump. As mentioned, a normal force can act to cause or increasefriction, which may occur in a time dependent manner. Such friction cancause wear, which may lead to failure of a component or components. Forexample, consider determining a normal force, which can includedetermining a normal deviation from an axis, and determining that acomponent contacts another component with the normal force, which may bedue to the normal deviation from an axis (e.g., radial deviation from alongitudinal axis). Such an assessment may be performed with respect totime to determine wear based on material properties, contact, motion,momentum, velocity, hysteresis (e.g., directional effects), etc.

As an example, consider a sucker rod centralizer (SRC) that aims toreduce rod coupling wear where the SRC can include a nonrotating sleevedesign that is tapered for rod tripping. Such a SRC can reduce torque indeviated wells and lower workover frequency by reducing rotationalrubbing and rod wear. SRCs may be included in vertical wellinstallations, for example, to reduce transmission of eccentric motionof a rotor to a rodstring wobble in the rodstring to the polished rod.

As an example, an installation can include at least five nonrotatingSRCs in a vertical well to reduce eccentric motion of a rotor from beingtransmitted to the rodstring. As an example, an installation can includeone SRC at about 3.7 m above the rotor head and one SRC on top of eachof the two full sucker rods. As an example, an installation of SRCs canhelp to reduce wobble in the rodstring from being transmitted to thepolished rod, which can help to reduce the life of the seal or stuffingbox. As an example, consider SRCs placements at the bottom of thepolished rod and at the bottom of the adjacent sucker rod. As anexample, an SRC can include a spindle made or 4140 hardened, tempered,stress-relieved tool steel and can include chromed rod couplings and aKEVLAR-NYLON copolymer sleeve. As an example, consider tubing sizes in arange from about 70 mm to about 120 mm and sucker rod sizes in a rangefrom about 20 mm to about 30 mm.

As to control of a sucker rod pump, a controller may be a variablefrequency controller, which may be referred to as a drive (e.g., avariable frequency drive). Such a controller can include circuitry thatprovides for motor speed and torque accuracy, low harmonics, and smoothspeed ramping. As an example, such a controller may be operatedaccording to a method such as the method 800 of FIG. 8 where smoothnesscan be controlled based at least in part on one or more of thedeterminations of the determination block 840 (e.g., and/or the block830). As an example, a controller may operate according to the system600. For example, a controller can include a system such as the system600 where a pump model and a system model are utilized in a loop orloops that can provide for prediction error being fed back to the systemmodel for tuning. As an example, a controller can include circuitry thatcan operate using one or more of the equations presented above. Forexample, a controller can operate using equations that account fornormal force that is normal to a longitudinal axis of one or morecomponents of an installation (e.g., sucker rod pump components, SRCs,tubing, etc.).

Referring again to the pull block 860 of FIG. 8 , a method can includeperforming a post-pull assessment. Such a method can include feedinginformation from a post-pull assessment to a tuning block that can tunea system model or other model. As an example, such tuning can providefor more accurately determining force and/or failure (e.g., wear, etc.).As an example, consider pulling sucker rods where sucker rods areexamined for wear, which can be noted with respect to normal direction,which may be azimuthally in 360 degrees with respect to a longitudinalaxis. In such an example, the normal direction at an angle or angles canbe utilized to determine whether equations adequately described wear atsuch an angle or angles.

As an example, data acquired from pulled equipment can be utilized toperform simulations that aim to arrive at such data at a correspondingtime. For example, where an operational history is recorded until a pulltime, that operational history may be utilized in a simulation that canbe iteratively repeated to reduce error between determined wear andactual wear via adjustment to one or more parameters of a model (e.g., aphysics based model, etc.). As a model can account for normal forces(e.g., with direction azimuthally), which can result in deviations(e.g., normal to a longitudinal axis, etc.), a process can be iterativeto match frictional wear to one or more components being a result ofnormal forces. Where materials may be abrasive and/or corrosive, a modelmay take one or more of those factors into account. For example,abrasive material such as sand can accelerate wear for a given timevarying normal force of a component that contacts another component(e.g., due to deviation from its longitudinal axis during cyclicalmotion) and/or a corrosive chemical environment can accelerate wear fora given time varying normal force of a component that contacts anothercomponent (e.g., due to deviation from its longitudinal axis duringcyclical motion).

As an example, a system can provide for estimation of a time where a rodguide (e.g., SRC) is worn such that metal to metal contact will occur(e.g., due to deviation from a longitudinal axis, etc.) with a normalforce that is predicted to cause wear to one or both of the metalcomponents. In such an example, a safety factor may be utilized to stopoperations and pull equipment prior to occurrence of metal to metalcontact. For example, consider contact with tubing where wear to tubingmay occur due to metal to metal contact. As explained, pulling can helpto reduce undesirable consequences, which can include wearing tubingsuch that tubing is to be replaced, wearing a rod or rods until failuresuch that a fishing job is to occur to “fish-out” the failed equipment,etc. Such undesirable consequences can themselves place equipment and/orpeople at risk, while also being considered non- productive time (NPT),which may cause an operation or operations to not meet one or moreperformance indicators (PIs).

As an example, a system can be tuned based on post-pull data to improveperformance of the system and control of a pump system. In such anexample, post-pull data may come from one or more installations, whichmay benefit one or more on-going installations. As an example, a systemcan be improved by pulls at one or more other installation sites whilethe system controls pump operation at its site.

As an example, a system can provide for improving installation design.For example, consider improving SRC number and/or placement. As anexample, a number of SRCs may be increased and/or decreased andpositioned to reduce wear at one or more locations.

As to types of failures, one or more of the following may be consideredin a method such as the method 800 of FIG. 8 :

Polished rods

-   -   Not in center of tee throughout pumping cycle    -   Smaller than recommended by API    -   Top of carrier bar not horizontal    -   Crooked—not vertical—wellhead    -   Crooked hole near surface, with pony rods below the polished rod    -   Corrosion    -   Abrasion    -   Excessive heat    -   No lubrication    -   Packing too tight

Pony rods (rod subs)

-   -   Old subs used with new rod string    -   Improper API-grade rod    -   Sub directly below polished rod

Rod couplings (boxes)

-   -   Slimhole couplings used    -   Hammered-on boxes    -   Insufficient circumferential displacement    -   Dirty or improperly cleaned threads    -   Improper or no lubricant (should be a properly screened        inhibitor, not tubing or drillpipe dope)    -   End face not perpendicular to the threads    -   Oxygen in system    -   Couplings made from free-machining steels

Rod pins

Old-style, nonundercut pins

-   -   Incorrect circumferential displacement    -   Box and pin not made up, but broken out and remade on new C and        K rods    -   Box shoulder and pin shoulder not parallel    -   Rod upsets    -   Worn elevators    -   Rod bent while tailing out or in    -   Rods corkscrewed above the pump during normal pumping    -   Rods corkscrewed after parting    -   Vibrations    -   Manufacturer's marks    -   Running too fast in the hole

Rod body

-   -   Inadequate/ineffective corrosion inhibition    -   Hydrogen embrittlement    -   Overload    -   Nicks    -   Service time exceeds fatigue life    -   Rough surface    -   Yield strength exceeded while attempting to unseat pump    -   Defective material    -   Oxygen allowed in the pumping system    -   Bends

Valve rod (stationary barrel pump)

-   -   Pump not centralized in tubing    -   Improper material    -   Plunger too short and pump not centralized    -   Crooked hole at pump setting depth    -   Pounding fluid

Pull tube (traveling barrel pump)

-   -   Pump not centralized in tubing    -   Pull tube buckling on downstroke    -   Improper material    -   Pump set too deep for pull-tube length    -   Pounding fluid

As to string replacement, replacing a rod string one rod at a time maybe suboptimal; thus, the economic life of a rod string can be consideredif rods start to fail or, as explained with respect to FIG. 8 , areexpected to fail. In various practices, a rod-string section may bereplaced after two or three failures, while the entire rod string may bereplaced after three or four failures. As mentioned, a method caninclude post-pull assessments as to failure, which can be utilized insimulations to adjust one or more models and/or to design one or morepump system.

As an example, a post-pull assessment may not be able to assess a rootcause as failure may not have occurred (e.g., pulling prior to failure);however, a simulation may be performed given post-pull and operationalhistory to perform one or more simulations that indicate what would be aroot cause. For example, consider running a simulation forward in timeusing post-pull information from an assessment until a failure isreached, which may be assessed to determine whether the reason forpulling and/or the post-pull assessment correspond to the simulated rootcause of failure. Where the simulated root cause differs from anassessed likely root cause, one or more adjustments may be made to amodel or models (e.g., and/or solver) and/or a post-pull assessmentprocess such that agreement is reached as to what is the likely rootcause (e.g., was simulation indicative or was assessment indicative, ora combination of both?).

FIG. 9 shows a diagram 900 that illustrates stress corrosion cracking(SCC), which is a type of corrosion process (e.g., a degradationprocess), which may exist in an environment where a pump system isimplemented. As shown, SCC may occur given a susceptible material, acorrosive environment and a tensile stress that is greater than or equalto a stress threshold. In terms of temporal aspects, the threeconditions represented in the Venn type of diagram 900 may occursimultaneously to promote SCC. SCC can cause a material or part to failat a stress level below a material-rated yield strength (e.g., afrangible degradation mechanism).

SCC involves growth of crack formation in a corrosive environment andcan lead to unexpected sudden failure of normally ductile metalssubjected to a tensile stress, particularly at elevated temperature. SCCcan be highly chemically specific in that certain alloys are likely toundergo SCC when exposed to a small number of chemical environments. Thechemical environment that causes SCC for a given alloy is often onewhich is mildly corrosive to the metal otherwise. Hence, metal partswith severe SCC can appear bright and shiny, while being filled withmicroscopic cracks. SCC may progress rapidly. Stresses can be the resultof the crevice loads due to stress concentration, or can be caused bythe type of assembly or residual stresses from fabrication (e.g. coldworking). As an example, in some instances, residual stresses can berelieved at least in part by annealing and/or one or more other types ofsurface treatments.

As an example, a material or alloy can be susceptible to SCC (e.g.,stronger or harder the material, the more susceptible to fractureproviding the environment is conducive to SCC). As an example, anenvironment amenable to SCC may include one or more corrosive substances(e.g., halides like chlorides, etc.) and may be of a temperature thatpromotes kinetics, thermodynamics and/or mechanical degradation (e.g.,expansion, different thermal conductivities, etc.). As an example, themore corrosive the conditions and the more likely fracture may occur asa result of imposed tensile stresses. As to tensile stresses, thegreater the tensile stresses, the sooner a fracture or fractures maydevelop; further, below a certain threshold, cracking may not occurunless the environment or materials are made more amenable tostress-corrosion cracking.

During installation, use and/or removal of a rod string in a bore of awell, which may be a bore of casing, a joint can come into contact withwell fluid. For example, well fluid may enter a clearance between a rodand a coupling and come into contact with threads. As an example, sourgas may contact threads. In such an example, the threads may be in asour gas environment (e.g., in an environment that includes sour gas).

Sour gas can be a term that characterizes gases that are acidic eitheralone or when associated with water. Two examples of sour gasesassociated with oil and gas drilling and production are hydrogensulfide, H₂S, and carbon dioxide, CO₂. Sulfur oxides and nitrogenoxides, generated by oxidation of certain sulfur- or nitrogen-bearingmaterials, can be in such a category but tend not to be found inanaerobic subsurface conditions.

As an example, a physics-based model can include one or more terms thatcan account for environmental conditions, which may include one or morestress-related environmental conditions that may affect integrity ofpump equipment.

FIG. 10 shows an example of a method 1000 that includes an operationblock 1010 for operating a pump system, a determination block 1020 fordetermining a condition associated with a pump system, and a controlblock 1030 for controlling the pump system based at least in part on thecondition. As an example, the method 1000 may be implemented at least inpart via a controller. As an example, the method 1000 may be implementedat least in part via a computing system, which may optionally be orinclude one or more controller components (e.g., interfaces, etc.,operatively coupled to one or more pieces of field equipment).

FIG. 11 shows an example of a pumping unit 1100, which includes variousdimensions. While referred to as a “unit”, as can be discerned, thepumping unit 1100 is an assembly of various components configured tooperatively coupled to a rodstring for purposes of pumping fluid. Thepumping unit 1100 may be referred to as an assembly or a system. Adocument entitled “Conventional Pumping Unit” is incorporated byreference herein (https://www.slb.com/˜/media/Files/artificiallift/product sheets/rodlift/conventional-pumping-unit-ps.pdf), whichprovides various specifications with respect to the pumping unit 1100,for example, depending on model type (e.g., C80 to C1280), etc.(Schlumberger Limited, Houston, TX, brochure/document 18-AL-405851).Such a pumping unit or other type of pumping unit can be part of apumping system that can be considered in a method such as the method1000 of FIG. 10 . Such a pumping system can include one or morecontrollers that can provide for control of one or more pumping units.

As an example, a method can include operating a pump system; determininga condition associated with the pump system; and controlling the pumpsystem based at least in part on the condition. In such an example,determining can include utilizing a physics-based model that includestwo spatial dimensions and/or a physics-based model that includes threespatial dimensions. As an example, a 3D spatial model can provide formodeling buckling associated with a rodstring of a pump system. As anexample, modeling can include adjusting for acceleration to improve apump load model, for example, for estimating one or more gascharacteristics using the pump load model and/or estimating strokelength using the pump load model.

As an example, a pump system can be disposed at least in part in adeviated well (e.g., a well that deviates from vertical by a particularamount, etc.). In such an example, a method can include utilizing aphysics-based model that includes an axial dimension and a radialdimension as a dimension normal to the axial dimension.

As an example, a method can include determining a condition based on aforce measurement where the condition can be a position. Such a positioncan be a position in one or more spatial dimensions, which may or maynot vary with respect to time.

As an example, a pump system can include a sucker rod pump. As anexample, a condition can be a pump system condition and/or a wellcondition. As to the latter, consider, for example, a well conditionthat pertains to a well angle defined with respect to a verticaldirection (e.g., a deviated portion of a well, etc.). As an example, acondition can be a fluid condition.

As an example, a method can include utilizing a physics-based model togenerate training data, training a machine model utilizing the trainingdata to generate a trained machine model and where a condition is outputfrom the trained machine model responsive to receive of an inputassociated with operating the pump system. As mentioned, a method caninclude utilizing patterns such as for pattern recognition, which maybe, for example, via a trained model.

As an example, a system can include one or more processors; memoryaccessible to at least one of the processors; and processor-executableinstructions stored in the memory and executable by at least one of theprocessors to instruct the system to: operate a pump system; determine acondition associated with the pump system; and control the pump systembased at least in part on the condition. In such an example, the systemcan include at least one electrical interface that is operativelycoupled or operatively couple-able to at least one pump system forcontrol of at least one of the at least one pump system and/or foracquisition of data generated by one or more pump systems.

As an example, one or more computer-readable media can includecomputer-executable instructions executable to instruct a computingsystem to: operate a pump system; determine a condition associated withthe pump system; and control the pump system based at least in part onthe condition. Such one or more computer-readable media (CRM) may beutilized, for example, in a system, which may be a local system or maybe a distributed system. As an example, a system can be a field systemthat is operatively coupled to one or more pieces of field equipment forpurposes of data acquisition and/or control.

FIG. 12 shows components of a computing system 1200 and a networkedsystem 1210. The system 1200 includes one or more processors 1202,memory and/or storage components 1204, one or more input and/or outputdevices 1206 and a bus 1208. According to an embodiment, instructionsmay be stored in one or more computer-readable media (e.g.,memory/storage components 1204). Such instructions may be read by one ormore processors (e.g., the processor(s) 1202) via a communication bus(e.g., the bus 1208), which may be wired or wireless. The one or moreprocessors may execute such instructions to implement (wholly or inpart) one or more attributes (e.g., as part of a method). A user mayview output from and interact with a process via an I/O device (e.g.,the device 1206). According to an embodiment, a computer-readable mediummay be a storage component such as a physical memory storage device, forexample, a chip, a chip on a package, a memory card, etc.

According to an embodiment, components may be distributed, such as inthe network system 1210. The network system 1210 includes components1222-1, 1222-2, 1222-3, . . . 1222-N. For example, the components 1222-1may include the processor(s) 1202 while the component(s) 1222-3 mayinclude memory accessible by the processor(s) 1202. Further, thecomponent(s) 1222-2 may include an I/O device for display and optionallyinteraction with a method. The network may be or include the Internet,an intranet, a cellular network, a satellite network, etc.

As an example, a device may be a mobile device that includes one or morenetwork interfaces for communication of information. For example, amobile device may include a wireless network interface (e.g., operablevia IEEE 802.11, ETSI GSM, BLUETOOTH®, satellite, etc.). As an example,a mobile device may include components such as a main processor, memory,a display, display graphics circuitry (e.g., optionally including touchand gesture circuitry), a SIM slot, audio/video circuitry, motionprocessing circuitry (e.g., accelerometer, gyroscope), wireless LANcircuitry, smart card circuitry, transmitter circuitry, GPS circuitry,and a battery. As an example, a mobile device may be configured as acell phone, a tablet, etc. As an example, a method may be implemented(e.g., wholly or in part) using a mobile device. As an example, a systemmay include one or more mobile devices.

As an example, a system may be a distributed environment, for example, aso-called “cloud” environment where various devices, components, etc.interact for purposes of data storage, communications, computing, etc.As an example, a device or a system may include one or more componentsfor communication of information via one or more of the Internet (e.g.,where communication occurs via one or more Internet protocols), acellular network, a satellite network, etc. As an example, a method maybe implemented in a distributed environment (e.g., wholly or in part asa cloud-based service).

As an example, information may be input from a display (e.g., consider atouchscreen), output to a display or both. As an example, informationmay be output to a projector, a laser device, a printer, etc. such thatthe information may be viewed. As an example, information may be outputstereographically or holographically. As to a printer, consider a 2D ora 3D printer. As an example, a 3D printer may include one or moresubstances that can be output to construct a 3D object. For example,data may be provided to a 3D printer to construct a 3D representation ofa subterranean formation. As an example, layers may be constructed in 3D(e.g., horizons, etc.), geobodies constructed in 3D, etc. As an example,holes, fractures, etc., may be constructed in 3D (e.g., as positivestructures, as negative structures, etc.).

Although only a few examples have been described in detail above, thoseskilled in the art will readily appreciate that many modifications arepossible in the examples. Accordingly, all such modifications areintended to be included within the scope of this disclosure as definedin the following claims. In the claims, means-plus-function clauses areintended to cover the structures described herein as performing therecited function and not only structural equivalents, but alsoequivalent structures. Thus, although a nail and a screw may not bestructural equivalents in that a nail employs a cylindrical surface tosecure wooden parts together, whereas a screw employs a helical surface,in the environment of fastening wooden parts, a nail and a screw may beequivalent structures. It is the express intention of the applicant notto invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of theclaims herein, except for those in which the claim expressly uses thewords “means for” together with an associated function.

What is claimed is:
 1. A method comprising: operating a pump system;determining a condition associated with the pump system, wherein thecondition comprises a rod failure time, a rod guide failure time, or atubing wear parameter; and controlling the pump system based at least inpart on the condition.
 2. The method of claim 1, wherein the determiningutilizes a physics-based model that includes two spatial dimensions. 3.The method of claim 1, wherein the determining utilizes a physics-basedmodel that includes three spatial dimensions.
 4. The method of claim 3,further comprising modeling buckling associated with a rodstring of thepump system.
 5. The method of claim 1, further comprising adjusting foracceleration to improve a pump load model.
 6. The method of claim 5,further comprising estimating one or more gas characteristics using thepump load model and/or estimating stroke length using the pump loadmodel.
 7. The method of claim 1, wherein the pump system is disposed atleast in part in a deviated well.
 8. The method of claim 7, wherein thedetermining utilizes a physics-based model that includes an axialdimension and a radial dimension as a dimension normal to the axialdimension.
 9. The method of claim 1, wherein the determining is based ona force measurement and the condition is a position.
 10. The method ofclaim 1, wherein the pump system comprises a sucker rod pump.
 11. Themethod of claim 1, wherein the determination uses a dynamometer cardshape analysis.
 12. The method of claim 1, wherein the conditioncomprises a rod failure time.
 13. The method of claim 1, wherein thewell condition comprises a rod guide failure time.
 14. The method ofclaim 1, wherein the condition comprises a tubing wear parameter. 15.The method of claim 1, further comprising utilizing a physics-basedmodel to generate training data, training a machine model utilizing thetraining data to generate a trained machine model and wherein thecondition is output from the trained machine model responsive to receiveof an input associated with operating the pump system.
 16. A systemcomprising: one or more processors; memory accessible to at least one ofthe processors; and processor-executable instructions stored in thememory and executable by at least one of the processors to instruct thesystem to: operate a pump system; determine a condition associated withthe pump system, wherein the condition comprises a rod failure time, arod guide failure time, or a tubing wear parameter; and control the pumpsystem based at least in part on the condition.
 17. The system of claim16, further comprising at least one electrical interface that isoperatively coupled to at least one pump system for control of at leastone of the at least one pump system.
 18. One or more computer-readablemedia comprising computer-executable instructions executable to instructa computing system to: operate a pump system; determine a conditionassociated with the pump system, wherein the condition comprises a rodfailure time, a rod guide failure time, or a tubing wear parameter; andcontrol the pump system based at least in part on the condition.
 19. Theone or more computer-readable media of claim 18, wherein the conditioncomprises a rod failure time, a rod guide failure time, and a tubingwear parameter.
 20. The one or more computer-readable media of claim 18,wherein the pump is controlled to extend the rod failure time, to extendthe rod guide failure time, or to decrease the tubing wear time.